Axial flow turbine

ABSTRACT

The present invention relates to an axial flow turbine, comprising: a rotor mounting part; a housing having a fluid supply part surrounding the rotor mounting part; a rotor which is installed at a rotation shaft installed in the housing and has a plurality of blades installed in a circumferential direction; and a plurality of injection nozzles, installed in the fluid supply part surrounding the rotor mounting part, for spraying a high-pressure fluid toward the blades, wherein the fluid collision surface of the blades installed at the rotor is formed to be inclined at an angle in the rotational direction of the rotor with respect to the normal axis of the rotation center axis, and the injection nozzles formed in the fluid supply part are installed at an angle parallel to the normal direction of the fluid collision surface of the blades. Due to the aforementioned configuration, the present invention provides the effect of maximizing the rotation rate of a turbine while smoothing fluid flow by optimizing the angle of the fluid collision surface of the blades.

TECHNICAL FIELD

The present invention relates to an axial flow turbine, and more particularly to an axial flow turbine having improved blade angle of a rotor thereof.

BACKGROUND ART

As general examples of a gas turbine or a steam turbine used in power generation plants and the like, there are an axial flow turbine, in a rotation shaft direction of which a fluid flows due to a direction of the flow of a working fluid, an oblique flow turbine, wherein a fluid flows diagonal to a rotation shaft, a radial turbine, in a radial direction of which a fluid flows, and the like. Thereamong, an axial flow turbine is suitable for medium or large-capacity power generation plants, and thus, is broadly used as a steam turbine and the like in large thermal power plants.

From the viewpoint of economic efficiency increase and environmental load reduction, increase in power generation efficiency of a power generation plant is required, and high performance of an axial flow turbine is an important issue. As factors determining the performance of a turbine, there are short-circuit loss, exhaust loss, mechanical loss, and the like. In particular, it is recognized that reduction of short-circuit loss is effective in improving performance. Although there are various types of short-circuit loss, short-circuit loss types may be broadly classified into airfoil loss caused by blade shape per se, secondary flow loss caused by flow crossing a flow channel between blades, leakage loss due to leakage of a working fluid out of a flow channel between blades, and the like. Thereamong, leakage loss includes bypass loss wherein the energy of steam is not effectively utilized due to a leakage flow flowing along a path other than a main stream path; mixing loss occurring when a leakage flow out of a main stream is introduced into the main stream again; interference loss occurring due to interference of reintroduced leakage flow with a downstream cascade; and the like. Accordingly, in reducing leakage loss, it is important to reintroduce a leakage flow into a main stream, without loss of the leakage flow, while reducing a leakage flow amount.

In view of this, Japanese Patent Application Publication No. 2011-106474 proposes a technology for installation of a guide plate for guiding a leakage flow at leakage flow path parts of the same end portions of blades. By the guide plate, a leakage direction of a leakage flow coincides with the direction of a main stream discharged from the same blades, thereby reducing mixing loss when a leakage flow joins a main stream.

However, such a conventional axial flow turbine have difficulties in minimizing loss out of a main stream, leakage loss, and short-circuit loss occurring due to collision of a fluid against blades.

Korean Patent Application Publication No. 10-0550366 discloses a multistage axial flow turbine.

DISCLOSURE Technical Problem

Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide an axial flow turbine that may reduce main stream loss, leakage loss, and mixing loss, as energy loss due to flow of a fluid, and exhibit relatively high turbine efficiency.

Technical Solution

In accordance with one aspect of the present invention, provided is an axial flow turbine including a rotor mounting part;

a housing including a fluid supply part that surrounds the rotor mounting part;

a rotor installed at a rotation shaft at the housing, located at a rotor mounting part, and including a plurality of blades mounted thereon in a circumferential direction; and

a plurality of injection nozzles installed at a fluid supply part surrounding the rotor mounting part and provided to spray a high-pressure fluid to fluid collision surfaces of the blades,

wherein fluid collision surfaces of the blades mounted on the rotor are formed to be inclined in a rotation direction of the rotor with respect to a normal direction axis of a rotation center axis, and the injection nozzles formed at the fluid supply part are installed at an angle parallel to a normal direction of fluid collision surfaces of the blades.

In the present invention, fixing blades installed between the blades, which are installed at the rotor, and the rotation shaft and guiding a fluid are installed at a supporter extending, in a rotation shaft direction, from the fluid supply part of the housing.

The fluid collision surfaces of the blades installed at the rotor are formed to be inclined at a predetermined angle with respect to a rotation center axis of the rotor.

In accordance with another aspect of the present invention, there is provided an axial flow turbine including a housing including at least one fluid inlet formed in an upper part thereof and a rotor mounting part formed therein; a rotation shaft rotatably installed at the housing and passing through the rotor mounting part; a rotor installed at the rotation shaft and including a plurality of a rotor rotation force generators formed at edge portions thereof,

wherein each of the rotor rotation force generators formed at the rotor includes a fluid induction part formed from an upper surface in a rotation direction; a blade formation part formed from the fluid induction part in a radial direction, formed to be inclined in a rotation direction with respect to a normal direction axis perpendicular to a rotation center axis of the rotor, and colliding with a fluid; and an induction discharge part protruding from the blade formation part to an outer circumferential surface of the rotor.

In the present invention, the induction discharge part is formed in a direction opposite to a rotation direction from the blade formation part, and fluid induction resistance protrusions are formed on an inner circumferential surface of the housing corresponding to the induction discharge part.

Advantageous Effects

As apparent from the fore-going, the present invention advantageously provides an axial flow turbine that reduces short-circuit loss and leakage loss occurring when a fluid sprayed from injection nozzles collides with each blade while smoothing the flow of a fluid by adjusting the angles of fluid action blades and the angles of fluid collision surfaces of blades which cause rotational action due to collision with a fluid, and thus provides an increased turbine rotation rate.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a partially-cut sectional view of an embodiment of an axial flow turbine according to the present invention.

FIG. 2 illustrates a partially-cut perspective view of an axial flow turbine according to the present invention.

FIG. 3 illustrates a cross-sectional view of the axial flow turbine illustrated in FIG. 1.

FIG. 4 illustrates a partially-cut perspective view of a rotor of the present invention.

FIG. 5 illustrates a sectional view of another embodiment of an axial flow turbine according to the present invention.

FIG. 6 illustrates a partially-cut perspective view of the rotor illustrated in FIG. 5.

FIG. 7 illustrates a graph representing a relationship between stream velocity and a revolution speed of each of an axial flow turbine according to the present invention and a conventional axial flow turbine.

BEST MODE

An embodiment of an axial flow turbine according to the present invention is illustrated in FIGS. 1 to 4.

Referring the figures, an axial flow turbine 10 according to the present invention includes a rotor mounting part 21 included therein; a housing 20 in which the rotor mounting part 21 and a fluid supply part 22 partitioned by a sectional partition wall 23 are formed; a rotor 40 which is installed at the rotor mounting part 21 installed at a rotation shaft 30 that is installed at the housing 20 and on which a plurality of blades 41 is mounted in a circumferential direction; and a plurality of injection nozzles 50 which is installed at the sectional partition wall 23 and is provided to rotate the rotor 40 by spraying a fluid supplied to the fluid supply part 22 onto fluid collision surfaces 42 of the blades 41.

A plurality of rotor mounting parts 21 may be installed to be stacked inside the housing 20 in a vertical direction of the rotation shaft 30, and the rotor 40 is installed at each of the rotor mounting parts 21. In addition, a fluid is supplied to the fluid supply part 22, which is partitioned, in a circumferential direction, by the sectional partition wall 23 at an outer circumferential surface of the rotor mounting part 21 located at the uppermost side, through at least one fluid supply pipe 24 installed at an upper surface or side surface of the fluid supply part 22.

In addition, a fluid supply part 22′ located at a lower part in a shaft direction communicates with the rotor mounting part 21 at an upper part in the shaft direction such that a fluid of the rotor mounting part 21 is introduced to the fluid supply part 22′.

As illustrated in FIGS. 3 and 4, the fluid collision surfaces 42 of the blades 41 mounted on the rotor 40 are formed to be inclined in a rotation direction of the rotor 40 with respect to a normal direction axis B of a rotation center axis C. An inclination angle a is preferably 5 to degrees. When the inclination angle a is set to 5 degrees or less, short-circuit loss interrupting collision of a fluid against the fluid collision surfaces of the blades 41 relatively increases. On the other hand, when the inclination angle a is 45 degrees or more, collision loss due to a main stream, i.e., the force component in a main stream direction, increases.

In addition, the injection nozzles 50 for spraying a fluid supplied from the fluid supply part 22 to the fluid collision surfaces 42 of the blades 41 are installed at an angle parallel to a normal direction of the fluid collision surfaces 42 of the blades 41. An injection hole of each of the injection nozzles 50 is preferably installed to correspond to the center of the fluid collision surfaces 42. In addition, preferably, an inner diameter of each of the injection nozzles 50 gradually increases from the injection hole of each of the injection nozzles 50 to the fluid supply part 22 so as to reduce loss in a tube, although not illustrated in the figures.

Meanwhile, the fluid collision surfaces 42 of the blades 41 installed at the rotor 40 are formed to be inclined at a predetermined angle with respect to the rotation center axis C of the rotor 40. The fluid collision surfaces 42 are formed to be inclined irrespective of the shapes of blades or installation angles thereof. Preferably, an inclination angle d of each of the fluid collision surfaces 42 is 0 to 65 degrees. When an inclination angle b of each of the fluid collision surfaces 42 with respect to the rotation center axis C is 65 degrees or more, the force component in the main stream direction increases, whereby an occurrence frequency of leakage loss relatively increases.

In addition, a supporter 25 extending, by a predetermined length, from a fluid supply part side in a rotation shaft direction is formed at a lower part of the sectional partition wall 23 of the housing 20. A through hole 26 is formed at the supporter 25 such that a fluid colliding with the fluid collision surfaces 42 of the blades 41 smoothly flows to the fluid supply part 22 at the lower part.

In addition, fixing blades 45 for guiding a fluid in the vicinity of inner end sides of the blades 41 are installed at a predetermined interval at an end side of the supporter 25 such that rotating blades 41 do not interfere with a fluid which has collided with the blades 41. The fixing blades are preferably formed to be inclined in a rotation direction of the rotor 40.

FIGS. 5 and 6 illustrate another embodiment of an axial flow turbine according to the present invention. In the embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals.

Referring to the figures, at least one fluid supply pipe 24 is formed at an upper part of the axial flow turbine 70 according to the present invention. In addition, the axial flow turbine 70 includes a housing 20 inside which a single rotor mounting part 21 is formed; a rotation shaft 30 which is rotatably installed at the housing 20 and passes through the rotor mounting part 21; and a plurality of rotors 90 including a plurality of rotor rotation force generators 80 that are formed at edge portions of the rotation shaft 30.

The rotors 90 are formed in a disk shape. The rotor rotation force generators 80, which are formed along edge portions of the rotors 90 and provide rotational force to the rotors 90 due to collision of a fluid, include a fluid induction part 81 formed from an upper surface of each of the rotors 90 in a rotation direction; a blade formation part 82 which is formed from the fluid induction part 81 in a radial direction to be inclined in a rotation direction with respect to a normal direction axis B perpendicular to a rotation center axis C of the rotors 90, so that a fluid introduced through the fluid induction part 81 collides with the blade formation part 82; and an induction discharge part 83 protruding from the blade formation part 82 to an outer circumferential surface of each of the rotors 90. The induction discharge part 83 is formed to be inclined in a direction opposite to a rotation direction from the blade formation part 82, and fluid induction resistance protrusions 27 are formed on an inner circumferential surface of the housing corresponding to the induction discharge part 83.

As illustrated in FIG. 6, an inclination angle a of the blade formation part 82 of each of the rotor rotation force generators 80 is preferably 5 to 45 degrees with respect to the normal direction axis B of the rotation center axis C. In addition, a fluid collision surface 85 of the blade formation part 82 installed at each of the rotors 90 is formed to be inclined at a predetermined angle with respect to the rotation center axis C of the rotors 90. The inclination angle of the fluid collision surface 85 is preferably 0 to 65 degrees.

The fluid induction resistance protrusions 27, which is formed on an inner circumferential surface of the housing 20 opposite to outer circumferential surfaces of the rotors 90, downwardly induce flow of a fluid discharged from the fluid induction discharge part 83, and includes at least one surface (not shown) corresponding to the fluid induction discharge part 83 of each of the rotors 90 such that reaction force due to collision of a fluid can act on the rotors 90.

Operation effects of the axial flow turbine according to the present invention having the aforementioned configuration are described below.

First, the present invention may maximize a rate of rotation of a turbine while providing smooth fluid flow by optimizing the angles of fluid action blade surfaces. Referring to FIGS. 1 to 4, a high-pressure fluid is introduced to the fluid supply part 22 via the fluid supply pipe 24 of the housing 20 of the axial flow turbine 10.

In addition, a high-temperature and high-pressure fluid introduced to the fluid supply part 22 is sprayed at high pressure through the injection nozzles 50 and collides with the fluid collision surfaces 42 of the blades 41 corresponding to the injection nozzles 50, thereby rotating the rotor 40 at high speed.

By such a process, the fixing blades 45 induce a fluid travel direction toward the through hole 26 through which the rotation shaft 30 passes such that interference of the blades 41 of the rotor 40 does not occur. Accordingly, re-mixing with a fluid colliding with the fluid collision surfaces 42 of the blades 41 may be prevented, thereby minimizing mixing loss of a fluid.

In particular, since the fluid collision surfaces 42 of the blades 41 of the rotor 40 according to the present invention are formed to be inclined in a rotation direction of the rotor 40 with respect to the normal direction axis B of the rotation center axis C, collision surfaces of a fluid sprayed from the injection nozzles may be more widely secured and interference resistance of the blades introduced to the injection nozzles 50 in succession during rotation of the blades 41 may be reduced. Accordingly, the effect that a fluid continuously collides with the blades 41 of the rotor 40 may be obtained, whereby short-circuit loss of a fluid sprayed from the injection nozzles 50 may be relatively reduced.

As illustrated in FIG. 7, the present inventors confirmed that the axial flow turbine according to the present invention provides a high revolution speed in the case of a low-speed fluid, i.e., at a relatively low stream velocity. More particularly, the axial flow turbine of the present invention provides the same revolution speed as that of a conventional axial flow turbine at a lower fluid injection rate. Accordingly, it can be confirmed that the efficiency of the axial flow turbine according to the present invention is relatively high.

Meanwhile, referring to FIGS. 5 and 6, in the case of the axial flow turbine 70 according to the present invention, action and reaction simultaneously act on the rotors 90 when the rotors 90 are driven by a high-temperature and high-pressure fluid. That is, a fluid introduced to the fluid induction part 81 of each of the rotor rotation force generators 80 primarily acts as rotational force of the rotors 90 while colliding with the blade formation part 82, and secondarily acts while being discharged through the fluid induction discharge part 83 formed in a direction opposite to the rotation direction. In particular, a fluid discharged through the fluid induction discharge part 83 causes a reaction while colliding with the fluid induction resistance protrusions 27, thereby increasing rotational force of the rotors 90.

In particular, since the blade formation part 82 is formed to be inclined in a rotation direction of the rotor with respect to the normal direction axis B of the rotation center axis C, collision surfaces of a fluid sprayed from the injection nozzles 50 may be relatively widely secured, thereby reducing fluid resistance.

The constituents of the present invention may be variously modified and may have various shapes.

While the present invention has been particularly shown and described with reference to the preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be appreciated by those skilled in the art that numerous changes and modifications of the invention are possible without departing from the spirit and scope of the appended claims. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. In addition, the blades and the blade surfaces of the present invention may have various shapes and forms depending upon a field situation or a fluid type within a range within which angle ranges of the blades and blade surfaces of the present invention are not affected.

INDUSTRIAL APPLICABILITY

The technical idea of an axial flow turbine of the present invention may be repeatedly practiced providing the same result. Particularly, the axial flow turbine of the present invention may be used in various power generating facilities and as industrial power source. 

1. An axial flow turbine, comprising: a rotor mounting part; a housing comprising a fluid supply part that surrounds the rotor mounting part; a rotor installed at a rotation shaft at the housing, located at a rotor mounting part, and comprising a plurality of blades mounted thereon in a circumferential direction; and a plurality of injection nozzles installed at the fluid supply part surrounding the rotor mounting part and provided to spray a high-pressure fluid to the blades, wherein fluid collision surfaces of the blades mounted on the rotor are formed to be inclined in a rotation direction of the rotor with respect to a normal direction axis of a rotation center axis, and the injection nozzles formed at the fluid supply part are installed at an angle parallel to a normal direction of fluid collision surfaces of the blades.
 2. The axial flow turbine according to claim 1, wherein fixing blades installed between the blades, which are installed at the rotor, and the rotation shaft and guiding a fluid are installed at a supporter extending, in a rotation shaft direction, from the fluid supply part of the housing.
 3. The axial flow turbine according to claim 1, wherein the fluid collision surfaces of the blades installed at the rotor are formed to be inclined at a predetermined angle with respect to a rotation center axis of the rotor.
 4. The axial flow turbine according to claim 3, wherein the fluid collision surfaces of the blades are inclined at an angle of 5 to 45 degrees in a rotation direction of the rotor with respect to the normal direction axis of the rotation center axis, and the fluid collision surface are inclined at a predetermined angle, i.e., at an angle of 0 to 65 degrees, with respect to the rotation center axis of the rotor.
 5. An axial flow turbine, comprising: a housing comprising at least one fluid inlet formed in an upper part thereof and a rotor mounting part formed therein; a rotation shaft rotatably installed at the housing and passing through the rotor mounting part; a rotor installed at the rotation shaft and comprising a plurality of a rotor rotation force generators formed at edge portions thereof, wherein each of the rotor rotation force generators formed at the rotor comprises a fluid induction part formed from an upper surface in a rotation direction; a blade formation part formed from the fluid induction part in a radial direction, formed to be inclined in a rotation direction with respect to a normal direction axis perpendicular to a rotation center axis of the rotor, and colliding with a fluid; and an induction discharge part protruding from the blade formation part to an outer circumferential surface of the rotor.
 6. The axial flow turbine according to claim 5, wherein the induction discharge part is formed in a direction opposite to a rotation direction from the blade formation part, and fluid induction resistance protrusions are formed on an inner circumferential surface of the housing corresponding to the induction discharge part. 